Eye growth in the aphakic newborn rabbit.

PURPOSE

To examine growth in unilaterally lensectomized newborn rabbits.

SETTING

S:t Erik Eye Hospital, Karolinska Institute, Stockholm, Sweden.

METHODS

Unilateral lensectomy was performed in 18 randomly selected 23-day-old rabbits. Corneal incision was performed in 2 other rabbits, and the aqueous humor was replaced with balanced salt solution in one eye. Axial length, corneal diameter, corneal thickness, intraocular pressure (IOP), and refraction were measured in all eyes preoperatively and 1, 2, and 3 months postoperatively. The wet mass of the after-cataract was measured 3 months after surgery.

RESULTS

The growth of the aphakic eye, as indicated by axial length and corneal diameter, was significantly less than that of the control eye in 14 rabbits. No significant difference in IOP or corneal thickness was found between the lensectomy and control eyes. Four animals had elevated IOP with secondary glaucoma and were excluded from the study. No difference in eye growth was found between the two eyes when no lensectomy was performed. Refraction in the unoperated eye showed a myopic shift. After lensectomy, the operated eye became hyperopic with a myopic shift 3 months after surgery. No correlation was found between eye growth and the wet mass of the after-cataract.

CONCLUSIONS

Our results suggest that removal of the rabbit crystalline lens at an early age reduces eye growth.